In the upstream Oil and Gas Industry, paraffin, wax and asphaltene deposits on the inside surface of production tubing in oil and gas wells reduce the cross sectional area of the pipe. The reduction in the cross sectional area increases the flowing friction pressures which can reduce or completely halt production from the producing well.
Currently there are many existing methods, procedures and chemicals employed by Operators to combat paraffin in oil fields around the world where paraffin problems occur. Some of these practices include: Circulating the well with Hot Oil or Hot Water; Wireline wax cutting with various diameter gauge ring cutters or wax knives; The injection of various chemicals, paraffin inhibitors, crystal modifiers, and solvents via capillary tube, surface applications and “squeezes”; There are anti-wax sticks available which are dropped down the annulus of the well, and magnetic devices claimed to alter or prevent the formation of paraffin crystals; and there are downhole electric heaters, with a surface supplied electrical power source to raise the temperature of produced fluids above the melting point of paraffin.
However, many of these methods have limited effect or application in controlling paraffin, some even cause additional operational problems, and the battle against paraffin continues to hamper oil production operations everywhere.
Without effective treatment or removal of paraffin, oil wells can quickly stop producing due to the lack of a continuous flow conduit to the surface, and in most cases requires that the tubing be pulled and replaced in order to resume production. The loss in oil productivity due to the reduction in flow rate caused by paraffin deposition, and the costs associated with Well Service work to replace tubing are two of the constant operational costs that Operators face while producing oil from paraffin prone oil and gas fields.
The hot anti-wax knife tool provides a new and previously unavailable method of cutting and melting a hole though the wax deposited in the production tubing in order to resume the flow of produced fluids. The tool is an invention borne of necessity.
Normally occurring paraffin wax has a melting temperature of about 90 degrees Celsius. With fully charged batteries, the tool can generate cutting edge temperatures well over 90 degrees Celsius for approximately 30 to 45 minutes, long enough for the tool to be assembled, and run down into the production tubing on Wireline, where it will melt and cut a hole through the paraffin deposits and restore production from the well.
Only since the advent of the Nickel Metal Hydride (Ni-MH) rechargeable battery, is it possible for size AA or AAA batteries to be arranged together in a direct current connection that is both series and parallel. Rechargeable batteries arranged in this manner can provide sufficient power to a heating element over a reasonable period of time, to elevate the temperature of the Cutting Head above the melting point of paraffin inside the tubing. The Ni-MH batteries arranged in this configuration provide a self contained source of electrical energy, augmenting the wax cutting effect of the tool with a heated edge to melt the wax that it contacts.
I have relied extensively on my own experience, education, knowledge of physics and skills to create and realize this idea and design, and the materials used to build the functional prototype were obtained locally. The reference data contained in the “Handbook of Physics” Walter Benenson, John W. Harris, Horst Stocker and Holger Lutz Editors, published in 2002 Springer-Verlag New York, Inc. also greatly aided in the design and creation of this invention.